Thanks for clarifying. I think however it's the wrong measure. There are industries that are as large or larger with as much if not more complexity that aren't failing to such a degree that their size is a systemic risk.

For example the US Real estate market is 7.4 Trillion, about 2X the size of the health care market with many more players and much more predicable outcomes. Finance and insurance are about the same size as well and are not terribly broken.

[1]https://en.wikipedia.org/wiki/Economy_of_the_United_States#G...